Unoprostone Isopropyl is a synthetic docosanoid and a structural analogue of an inactive biosynthetic cyclic derivative of arachidonic acid, 13,14-dihydro-15-keto-prostaglandin F 2a. Although the mechanism of action is unknown, unoprostone isopropyl is believed to reduce elevated intraocular pressure by increasing the outflow of aqueous humor through the trabecular meshwork. Unoprostone isopropyl (UI) may have a local effect on Big Potassium channels and ClC-2 chloride channels, but the exact mechanism is unknown at this time. Unoprostone is used for the management of open-angle glaucoma and ocular hypertension. The therapeutic efficacy of Unoprostone can be decreased when used in combination with Celecoxib, Diclofenac, Diflunisal, Etodolac and some other drugs. Unoprostone isopropyl ophthalmic solution may gradually increase the pigmentation of the iris, cause pigment changes (darkening) to periorbital pigmented tissues and eyelashes, exacerbate active intraocular inflammation (e.g., uveitis), and cause macular edema. In clinical studies, the most common ocular adverse reactions with use of Rescula were burning/stinging, burning/stinging upon drug instillation, dry eyes, itching, increased length of eyelashes, and injection. These were reported in approximately 10–25% of patients. Ocular adverse reactions occurring in approximately 5–10% of patients were abnormal vision, eyelid disorder, foreign body sensation, and lacrimation disorder. Other adverse reactions occurred more rarely.